New sesquiterpene lactones from Hemisteptia lyrata bunge

摘要

From the flowers of Hemisteptia lyrata, two new and two known guaianolides were isolated. The structures and relative configuration of the new compounds were established as 8alpha-O-2-hydroxymethyl-2-propenoyl-3beta-hydroxy-13-methoxy-4(15),10(14)-guaiadien-12,6-olide (1) and 3beta,8alpha-O-2-hydroxymethyl-2-propenoyl-3beta-hydroxy-13-methoxy-4(15),10(14)-guaiadien-12,6-olide (2), together with known compounds, isoamberboin (3) and 11,13-dihydro-deacylcynaropicrin (4). The structures were established by spectral data and X-Ray diffraction analysis.